Subtract 42/80 from 21/35
21/35 - 42/80 is 3/40.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 35 and 80 is 560
Next, find the equivalent fraction of both fractional numbers with denominator 560 - For the 1st fraction, since 35 × 16 = 560,
21/35 = 21 × 16/35 × 16 = 336/560 - Likewise, for the 2nd fraction, since 80 × 7 = 560,
42/80 = 42 × 7/80 × 7 = 294/560 - Subtract the two like fractions:
336/560 - 294/560 = 336 - 294/560 = 42/560 - After reducing the fraction, the answer is 3/40
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/35-42/80 21/35-84/80 21/70-42/80 63/35-42/80